Deformable wear face to backing connection for crusher plates



March 29, 1949. A. J. ROUBAL DEFORMABLE WEAR FACE TO BACKING CONNECTION FOR CRUSHER PLATES Filed Nov. 15, 1944 Patented Mar. 29, 1949 DEFORMABLE WEAR FACE TO BACKING CONNECTION FOR ORUSHER PLATES Alexander J. Roubal, Milwaukee, Wis., assignor to Allis-Chalmers Manufacturing Company, Milwaukee, Wis., a corporation of Delaware Application November 13, 1944, Serial No. 563,177

6 Claims. (Cl. 241-300) This invention relates to jaw crushers and in particular to jaw Crushers in which a heavy removable jaw plate, or wearing plate, is secured to the permanent jaw, or frame, of the crusher.

Such jaw plates are customarily made of hard, tough steel, such as manganese steel, which in operation may become deformed by repeated impacts of the rock or other material being crushed.

, The metal at the surface of the plate is peened by the impact of the material in such a manner that the surface layer tends to expand laterally causing the plate to warp and become convex, tending to pull the center of the plate away from the seat against which it is meant to be secured. This action throws a severe strain on the fastening bolts, frequently stretching them permanently so that the plate becomes loose and bears on the seat only at the corners. Operation of the crusher with the plates so warped and loosened may cause excessive and irregular Wear of the seat against which the jaw plate rests.

The object of the present invention is to provide a plate fastening which will securely hold the jaw plates in place regardless of deformation in service and prevent excessive strain on the f-astening means.

More particularly the invention consists in so forming portions of the jaw plate which are engaged by the holding bolts, that such portions will be deformable by forces below the yielding Fig.2 is a fragmentary, enlarged, sectional view .1;

of a portion of one of the jaw plates of Fig. 1 taken on the line II-II of Fig. 3;

' Fig. 3 is an enlarged view of a fragment of the face of one of the jaw plates shown in Fig. 1, with the holding down bolt removed.

Fig. 4 is a fragmentary, enlarged, sectional view of a portion of the crusher in Fig. 1, with an exaggerated showing of the effects of plate deformation on the fastening of the invention.

The drawing shows a typical installation of the improved jaw plate on a jaw crusher of otherwise known structure having a frame I and movable jaw 2 having jaw plate receiving seats 3 which may or may not be formed on renewable backin Plates 4.

Fastened on frame I and movable jaw 2 are a plurality of heavy steel jaw plates 6 formed with their rear faces adapted to fit against suitably formed seats 3. Intermediate the corners of such jaw plates are one or more counter bore recesses l which may be rectangular or otherwise formed to hold in non-rotatable relation the heads 8 of bolts 9, the shanks of which pass through bolt holes H in the jaw plates 0 and through bolt holes l2 in the frame i and jaw body 2, being secured at the rear end by nuts l3 to fasten plates 6 securely against their seats.

The foregoing structure is known. The present invention consists in forming the portions of the plates 5 which are clamped against the seats 3 as relatively thin webs or disks M of considerable lateral extent integrally joined at their peripheries with the jaw plates 6, as by hollowing out the plate annularly or radially around the innermost portion of the bolt head, that is coextensive with the inner surface of the web or fastening disk I 4 as shown at it.

The length of the bolt holes H, or the thickness of web or disk M, which is clamped at its center against the seat 3 by bolts 9 and bolt heads 8, and the diameter of disks [4 and hollows l6 are designed with reference to the characteristics of the material of which the disk I4 is formed, so that'the force required to substantially deflect the disk Hi outwards at its center relative to the plates 6 is less than the force required to permanently stretch, or break, bolts 9, that is, below the elastic strength or yielding strength of the bolts 9.

In operation, as the plates 6 become warped, the forces tending to stretch the bolts 9 will deform disks i l before attaining the degree required to stretch the bolts, and the disks will be deformed substantially as exaggeratedly shown in Fig. 4 of the drawing, the portions of disks I4 immediately between the bolt heads 8 and seats 3 remaining firmly clamped in place and fixing the jaw plates firmly against lateral motion on their seats through any normal amount of Warping occurring in service. Thus disks l4 cannot transmit tensile force snfficient to permanently stretch or break the bolts ii. Since bolts 9 will never become stretched or broken by Warpage of the jaw plates occurring in service, they will hold at least the corners of the plates 6 and the centers of discs or web-s i l firmly against the seats 3.

While a particular form of the invention is specifically described and illustrated hereinabove, it will be readily understood that the disks l4 need not be formed of the same material as the.

plates 6 and might be formed separately and joined as by welding (not shown) or might be other than round in shape. These and other modifications and equivalents which might occur to persons skilled in the art to which this invention appertains are intended to be included within the scope of this invention as defined by the appended claims.

It is claimed and desired to secure by Letters Patent:

1. In a jaw crusher, a crusher body, thick manganese steel jaw plates secured to said crusher body by bolts intermediate the corners of said plates, said plates being hollowed out radially around each bolt head to leave a relatively thin fastening Web, said web being perforated in a manner to provide a circumferentially continuous solid central portion closely surrounding the bolt shank and adapted to be gripped between the head of said bolt and said crusher body, said web being of such thickness and minimum lateral extent beyond the head of said bolt as to render the same deformable without rupture by forces normal to said such as may be exerted by said plate in warping due to natural expansion of the working surfaces, without exerting a tensile stress on the bolt beyond the elastic strength of said bolt.

2. in a crusher jaw structure at least one bolt,

a thick massive steel jaw plate to be secured to said crusher jaw by said bolt at a point intermediate the corners thereof, a relatively thin disklike fastening web integrally joined peripherally to said jaw plate and arranged to be clamped against said jaw at a central portion by the head of said bolt, said web being perforated in a manner to provide a circun'iferentially continuous solid central portion adapted to closely surround the bolt shank for engagement in clamping relation by the head of said bolt, said web being of such material, hickness and minimum radial extent beyond the head of said bolt as to be capabio of substantial deformation without rupture between said central portion and the periphery by forces normal to said web exerted by warpage of said jaw plate without stretching or breaking said bolt.

3. In a crusher structure in which a crusher plate is attached to a crusher body by fastening bolts having their heads countersunk in recesses in the workingiace and held against turning by the portion of the plate surrounding the recesses, with the bolt heads engaging the web of metal forming the bottom of the recess and bored to receive the shank of the bolt, a thick massive crusher plate of metal having a nialleability and bendability equivalent to that of manganese steel having its bolt holes recessed in the working face in a manner to receive suitably formed bolt heads in non-rotatable relation, the portion of the working face of said plate surrounding said recess being undercut substantially at the plane of the bottom of said recess in all directions from the periphery of said recess over a substantial area the minimum radial extent, thickness and bendability of said web of metal forming the bottom of recess being so chosen with relation to the effective head size and strength of said bolt as to render Web bendable without rupture by forces normal to its plane and of an order within the elastic strength of said bolt.

4-.- A crusher plate adapted to be secured to a crusher body by a bolt passed through the plate from the working face thereof and having its head engaging a web of metal surrounding the bolt shank, comprising a thick massive generally steel crusher plate, a bolt hole in said plate of diameter to pass the shank of a suitable bolt, a counterbore recess of substantial depth in the working face of said plate, said recess being of form adapted to receive a suitably formed bolt head in close fitting relation, the portion of the plate immediately surrounding said counterbore recess being undercut over a substantial area extending radially in all directions from the periphery of said recess substantially at the plane of the inner or bolt head engaged surface of the web of metal forming the bottom of said recess.

5. A thick massive crusher plate having a bolt head receiving recess extending from the working face of said plate through a major portion of the thickness thereof to leave a relatively thin bolting web at the bottom of said recess, said web eing bored to receive a suitable bolt shank, said recess being so formed and arranged that the portion of said plate surrounding the same will engage a suitably formed bolt head in close fitting non-rotatable relation, said portion of said plate surrounding said recess being undercut substantially in a plane coincident with the bottom of said recess in all directions from the periphery of said recess over a considerable area, in such a manner that said web will take the form of a relatively thin fastening web peripherally integral with said crusher plate and having an area substantially in ex ess of that of said recess.

5. A thick massive metal crusher jaw plate, having a counterbore recess in the working face of said plate for receiving the head of a suitable fastening bolt inserted from the working face, a

relatively thin metal bolting web integrally joined around its periphery with the metal of said plate and centrally bored to pass the shank of a suitable fastening bolt, the central portion of said web immediately surrounding the bore forming the bottom of said counterbore, said web extending laterally of said central portion and. beyond the lateral limits of said recess in all directions free of tensile stress transmitting connection in an axial direction with the metal of said plate immediately surrounding said recess over a substantial area between the lateral limits of said counterbore recess and the peripheral juncture of said web said plate.

ALEXANDER J. ROUBAL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,054,123 Hutchinson Feb. 25, 1913 1,309,&07 'rlcwhouse July 15, 1919 1,466,471 Bassett July 3, 1923 1392,9 53 Geyer a. Jan. 3, 1933 1,917,824) Brackett July 11, 1933 1,935,292 Chamberlain Nov. 1 1, 1933 1,986,144 Glick Jan. 1, 1935 2,058,257 Porteous Oct. 20, 1936 2,084,188 Buchanan June 15, 1937 FOREIGN PATENTS Number Country Date 774,326 France Oct. 1, 1934 178,729 Germany Nov. 17, 1906 96,207 Switzerland Septglfi, 1923 Certificate of Correction Patent No. 2,465,607. March 29, 1949.

ALEXANDER J. ROUBAL It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 4, line 2, claim 4, after the word generally insert rectangular;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 26th day of July, A. D. 1949.

THOMAS F. MURPHY,

Assistant Gammz'ssz'oner of Patents.

Certificate of Correction Patent No. 2,465,607. March 29, 1949.

ALEXANDER J. ROUBAL It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 4, line 2, claim 4, after the word generally insert rectangular;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 26th day of July, A. D. 1949.

THOMAS F. MURPHY,

Assistant Oommissz'oner of Patents. 

